Hypoxia-excited neurons in NTS send axonal projections to Kölliker-Fuse/parabrachial complex in dorsolateral pons
Autor: | Gang Song, Shawna M. MacDonald, Hui Wang, Chi-Sang Poon, Hui Xu |
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Rok vydání: | 2011 |
Předmět: |
Male
Chemoreceptor Solitary tract nucleus c-Fos Article Rats Sprague-Dawley Pons Neural Pathways Solitary Nucleus Animals Hypoxia Microinjection Medulla biology General Neuroscience Anatomy Commissure Axons Chemoreceptor Cells Rats nervous system Respiratory Mechanics biology.protein Brainstem Neuroscience circulatory and respiratory physiology |
Zdroj: | Neuroscience. 175:145-153 |
ISSN: | 0306-4522 |
DOI: | 10.1016/j.neuroscience.2010.11.065 |
Popis: | Hypoxic respiratory and cardiovascular responses in mammals are mediated by peripheral chemoreceptor afferents which are relayed centrally via the solitary tract nucleus (NTS) in dorsomedial medulla to other cardiorespiratory-related brainstem regions such as ventrolateral medulla (VLM). Here, we test the hypothesis that peripheral chemoafferents could also be relayed directly to the Kölliker-Fuse/parabrachial complex in dorsolateral pons, an area traditionally thought to subserve pneumotaxic and cardiovascular regulation. Experiments were performed on adult Sprague-Dawley rats. Brainstem neurons with axons projecting to the dorsolateral pons were retrogradely labeled by microinjection with choleras toxin subunit B (CTB). Neurons involved in peripheral chemoreflex were identified by hypoxia-induced c-Fos expression. We found that double-labeled neurons (i.e. immunopositive to both CTB and c-Fos) were localized mostly in the commissural and medial subnuclei of NTS and to a lesser extent in the ventrolateral NTS subnucleus, VLM and ventrolateral pontine A5 region. Extracellular recordings from the commissural and medial NTS subnuclei revealed that some hypoxia-excited NTS neurons could be antidromically activated by electrical stimulations at the dorsolateral pons. These findings demonstrate that hypoxia-activated afferent inputs are relayed to the Kölliker-Fuse/parabrachial complex directly via the commissural and medial NTS and indirectly via the ventrolateral NTS subnucleus, VLM and A5 region. These pontine-projecting peripheral chemoafferent inputs may play an important role in the modulation of cardiorespiratory regulation by dorsolateral pons. |
Databáze: | OpenAIRE |
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